Steam-shovel mechanism



Jan. 27, 1925. 1,524,100

D.S.MULUN STEAM SHOVEL MECHANISM Filed Nov. 1, 1921 Patented Jan. 27,1925.

UNITED STATES.

PATENT OFFICE;

DONALD-S. MULLIN,'OF STATE COLLEGE BOROUGH. PENNSYLVANIA, ASSIGNOR OFONE-HALF TO ROBERT SWAN, 33.,

OF 'PIT'ISBURGH, PENNSYLVANIA.

STEAIVDSHOVEL MECHANISM.

Application filed November 1, 192-1.

To (ZZZ whom may concern:

Be it known that I, DONALD S. MULnIN,

a citizen of the United States, and residing in the borough of StateCollege, in the county of Center and State of Pennsylvania, haveinvented or discovered thenew, useful, and Improved Steam-ShovelMechanism, of which the following is a speoifica tiOILr My inventionconsists in new and imsteam shovel scoops.

In the present practice the scoopbottom is unlatched or released, todump the load, by means of a pull rope .which the operator grasps andpulls atthe proper moment; but as the operator usually. requires bothhands tooperate the various control levers of the steam shovel, thismethod forces him to take his hand. from one of said levers when hedesires to reach for-the release rope.

This is inconvenient and often perilous.

The object which I have in view is the provision of .ineans whereby thescoop bottom may. be released by the operator-without his takingeitherof his hands from the control.

I obtain this advantageous result by con-' necting the pull rope topower-operated means which are controlled from one of the said controllevers but in. such a manner as notto. interfere with the main ororiginal functions of the saidlever.

Thus,..in theembodimentof theprinci- .ples of .my invention shown in theaccompanying drawings, I show the pull rope operated by means of a fluidpressure or steani-cylinder to which power is admitted. by a valvecontrolled by-one of-the main control levers ofthe steam shovel, saidmain; control lever being so modified that theoperator may, with onehand :on the lever, cause it to accomplish not only. its.

main functions in the usual.mannerbutmay ,also, without affecting saidmain functions, release thescoop .bottom whenever. it is desired .to 1dump the load.

I also provide new and improved fluid pressure means for releasing the:bottom, ;.said .means being shown controlled from one. of. the maincontrol levers of the steam' pressure admissioirand relief valvemechanism for said fluid pressure means.

Serial No; 512,124.

Other novel features of construction and.

arrangement of parts will appear from the following description.

In the accompanying drawings, which are however merely intended to beillustra tive ofthe principles of my invention without limiting thescope of the same to the construction shown, Fig. 1 is a side elevasteamcylinder which operates the pull rope, and its associated parts; Fig. 3is a detail of the steam valve and its control,

and Fig. 4- is an enlarged detail, with the boom: shown in section,illustrating .the housing for the sliding multiple block over which thepull rope runs.

The following is a detailed description of the drawings A representsthecab of the steam shovel, rotatably mounted in the usual way onthetruck B.

C represents the mast pivoted at its foot on a horizontal axis. Drepresents the crowding boom both swingingly and slidably mounted onthemast C. E represents the bucket or scoop pivotably mounted on the end ofthe boom and. controlled in the usual manner fromthe cab. I have simplyindicated these parts without showing the means for operatingthe same,as they are familiar to those skilled in the art and inJEIIGHISQIVESJIOIITI no part of the present invention.

The operation of the same however controlled in the usual manner bylevers in the cab. which the engineer grasps when operating the machine.I have indicated one of said levers at I it being immaterial which oneof the said control levers is selected for my purpose.

G represents the bottom of the scoop E. the same being'hinged to thescoop and normally held in its closed position by the sliding latch orbolt 1 which is connected by the chain 2 to an intermediate point on thelever 3 whose one end is pivoted to the boom D while its other end-isattached to the pull rope i, so-that a tug on said rope will release thelatch 1 and permit the bot tom to drop and dump the load.-

The rope 4 is'run aroundthe pairof triple or multiple blocks H and I,the end of said rope beingattached to one of said blocks, such as to theblock H at 5. The block H is journaled in a fixed position at the sideof the mast, as by the bracket 6, while the block I is mounted to slidebetween the two guides 7 attached to the side of the mast. Said block Iis mounted on the protruding end of the piston rod 8 attached to thepiston 9 of the single-acting steam cylinder J mounted on the side ofthe mast. 10 is a helical spring coiled about the piston rod 8 betweenthe block I and the head of the cylinder J thereby tending to slack thepull rope 4 and permit the bottom G tovclose and latch.

The forward end of said cylinder J is provided with a port 11communicating with valve chamber K having an inlet port 12 and a smalleroutlet port 13. 14 is aro'cking lever in said chamber pivotallysupported intermediate of its ends on a depending post or bracket 15.One end of said lever is provided with a valve 16 adapted to close theinlet port 12, while the other end of said lever is provided with avalve 17' adapted to close the outlet port 13. A helical spring 18normally holds the lever in position to close the inlet port and openthe outlet port. 19 is a steam pipe connected to the inlet port 12 andleading down alongthe mast C to a flexible joint 20 axially' alined withthe pivotal axis of said mast;

. and 21 is a pipe in the cab and connecting said joint to the boiler ormain steam supply.

22 is a slide valve interposed in the pipe 21 having its plug 23attached by a loose pivot connection to the lower end of the bell cranklever 24: having its apex pivotally mounted on the front wall of the cabwhile its upper end is connected bythe link 25 to the projecting arm 26rigidly attached to the hand grip 27 of the said control lever F. Thesaid hand grip 27 is pivotally connected to the upper end of the lever Fin such a manner as to be tiltable in relation to the lever in onedirection and that at substantially right angles to the path in whichthe lever is moved in performing its main con 7 trol functions. Thepivotal connection be-- tween the upper end of the bell crank lever 5 24and the lower end of the link 25 is horiin which-the grip is thrownover, and, vice versa, the swinging of said grip back into the position"shown, in alinement with. the lever F, will result in closing saidvalve. I have shown the grip adapted to be swung down toward the left asthe same is preferable inthe case of a lever worked with the right handof the operator, but if the steam valve 22 is to be operated inconnection with a left hand lever, the grip would preferably be arrangedto swing toward the right.

IV hen steam is admitted to the pipe 19 by opening the valve 22, itautomatically forces open the inlet valve 16, by compressing the spring18, and closes the outlet valve 17. The steam enters the port 11,causing the piston 9 to retreat in the cylinder J thus separating theblocks H and I, and, by shortening the pull rope, unlatching the scoopbottom. hen the valve 22 is closed, the pressure falls in the pipe 19,permitting the spring 18 to close the inlet port 12 and open the outletport 13 thus relieving the pressure in front of the piston 9 and thuspermitting the spring .10 to move the block I toward the stationaryblock H, thus lengthening the pull rope and permitting the bottom toclose and latch. A weight 28 is provided to insure against the ropeslacking between the blocks H and I as they approach.

The amount of slack required to be taken up in the pull rope before thelatch is re leased, of course, varies with the position of the dipperrelative to the mast, but this is taken care of by the shock absorbingtendency of the rope, as well as by the operator by regulating theamount of steam which is admitted to the cylinder J and consequently thedistance which the piston 9 is caused to retreat in the cylinder.

The relief port 13 of the valve chamber K is preferably connected by apipe 30 with the main steam exhaust pipe of the steam shovel whichusually extends to the top of the mast C.

It is evident from the foregoing that my invention greatly improves andfacilitates the control of the operation of the steam shovel, as thesame not only renders such operation more convenient, but it enables thecontents of the scoop to be accurately placed when dumped.

What I desire to claim is 1. In combination with a steam shovel providedwith a swinging hand lever to control the operation of the same andhaving a V scoop with a hinged bottom and a latch to hold said bottomclosed, a fluid pressure cylinder and piston, a steam pipe leading intosaid cylinder mounted on a mast, an operative connection between saidlatch and said piston consisting of a lever mounted on a boom and havingconnection with the latch. a bracket on the mast, a block journaled onsaid bracket, a rope on said block, said rope being connected at one endto said last mentioned lever, guides on the mast, a block slidable insaid guides and being connected to the piston, said rope being connectedat its other end to said slidable block, a. hand grip pivoted to thehand lever to control admission of steam from the steam pipe against thepiston to operate said operative connection to release said latch andthereby dump the contents of the scoop.

2. In combination with a steam shovel provided with a swinging handlever for controlling the operation of the same and having a scoop Witha hinged bottom and a latch to hold said bottom closed, a fluid pressurecylinder and piston on a mast, a steam pipe leading into said cylinder,an operative connection between said latch and said. piston consistingof a flexible member carried by a boom and the mast, guides on the mast,a slidable block in the guides having connection With the flexiblemember, a spring on the piston rod between the slidable block and thecylinder for operating the piston to alloW the latch to return tooperative position and means mounted on the lever to control admissionof steam from the steam pipe against the piston to operate saidoperative connection to release the latch and thereby dump the contentsof the scoop.

Signed at State College, Pa, this 25th day of July, 1921.

DONALD S. MULLIN,

